xref: /netbsd-src/bin/pax/pat_rep.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: pat_rep.c,v 1.27 2007/05/04 21:19:36 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992 Keith Muller.
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Keith Muller of the University of California, San Diego.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if HAVE_NBTOOL_CONFIG_H
37 #include "nbtool_config.h"
38 #endif
39 
40 #include <sys/cdefs.h>
41 #if !defined(lint)
42 #if 0
43 static char sccsid[] = "@(#)pat_rep.c	8.2 (Berkeley) 4/18/94";
44 #else
45 __RCSID("$NetBSD: pat_rep.c,v 1.27 2007/05/04 21:19:36 christos Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 #include <sys/time.h>
51 #include <sys/stat.h>
52 #include <sys/param.h>
53 #include <stdio.h>
54 #include <ctype.h>
55 #include <string.h>
56 #include <unistd.h>
57 #include <stdlib.h>
58 #include "pax.h"
59 #include "pat_rep.h"
60 #include "extern.h"
61 
62 /*
63  * routines to handle pattern matching, name modification (regular expression
64  * substitution and interactive renames), and destination name modification for
65  * copy (-rw). Both file name and link names are adjusted as required in these
66  * routines.
67  */
68 
69 #define MAXSUBEXP	10		/* max subexpressions, DO NOT CHANGE */
70 static PATTERN *pathead = NULL;		/* file pattern match list head */
71 static PATTERN *pattail = NULL;		/* file pattern match list tail */
72 static REPLACE *rephead = NULL;		/* replacement string list head */
73 static REPLACE *reptail = NULL;		/* replacement string list tail */
74 
75 static int rep_name(char *, size_t, int *, int);
76 static int tty_rename(ARCHD *);
77 static int fix_path(char *, int *, char *, int);
78 static int fn_match(char *, char *, char **);
79 static char * range_match(char *, int);
80 static int checkdotdot(const char *);
81 #ifdef NET2_REGEX
82 static int resub(regexp *, char *, char *, char *);
83 #else
84 static int resub(regex_t *, regmatch_t *, char *, char *, char *, char *);
85 #endif
86 
87 /*
88  * rep_add()
89  *	parses the -s replacement string; compiles the regular expression
90  *	and stores the compiled value and its replacement string together in
91  *	replacement string list. Input to this function is of the form:
92  *		/old/new/pg
93  *	The first char in the string specifies the delimiter used by this
94  *	replacement string. "Old" is a regular expression in "ed" format which
95  *	is compiled by regcomp() and is applied to filenames. "new" is the
96  *	substitution string; p and g are options flags for printing and global
97  *	replacement (over the single filename)
98  * Return:
99  *	0 if a proper replacement string and regular expression was added to
100  *	the list of replacement patterns; -1 otherwise.
101  */
102 
103 int
104 rep_add(char *str)
105 {
106 	char *pt1;
107 	char *pt2;
108 	REPLACE *rep;
109 #ifdef NET2_REGEX
110 	static const char rebuf[] = "Error";
111 #else
112 	int res;
113 	char rebuf[BUFSIZ];
114 #endif
115 
116 	/*
117 	 * throw out the bad parameters
118 	 */
119 	if ((str == NULL) || (*str == '\0')) {
120 		tty_warn(1, "Empty replacement string");
121 		return -1;
122 	}
123 
124 	/*
125 	 * first character in the string specifies what the delimiter is for
126 	 * this expression.
127 	 */
128 	for (pt1 = str+1; *pt1; pt1++) {
129 		if (*pt1 == '\\') {
130 			pt1++;
131 			continue;
132 		}
133 		if (*pt1 == *str)
134 			break;
135 	}
136 	if (*pt1 == 0) {
137 		tty_warn(1, "Invalid replacement string %s", str);
138 		return -1;
139 	}
140 
141 	/*
142 	 * allocate space for the node that handles this replacement pattern
143 	 * and split out the regular expression and try to compile it
144 	 */
145 	if ((rep = (REPLACE *)malloc(sizeof(REPLACE))) == NULL) {
146 		tty_warn(1, "Unable to allocate memory for replacement string");
147 		return -1;
148 	}
149 
150 	*pt1 = '\0';
151 #ifdef NET2_REGEX
152 	if ((rep->rcmp = regcomp(str+1)) == NULL) {
153 #else
154 	if ((res = regcomp(&(rep->rcmp), str+1, 0)) != 0) {
155 		regerror(res, &(rep->rcmp), rebuf, sizeof(rebuf));
156 #endif
157 		tty_warn(1, "%s while compiling regular expression %s", rebuf,
158 		    str);
159 		(void)free((char *)rep);
160 		return -1;
161 	}
162 
163 	/*
164 	 * put the delimiter back in case we need an error message and
165 	 * locate the delimiter at the end of the replacement string
166 	 * we then point the node at the new substitution string
167 	 */
168 	*pt1++ = *str;
169 	for (pt2 = pt1; *pt2; pt2++) {
170 		if (*pt2 == '\\') {
171 			pt2++;
172 			continue;
173 		}
174 		if (*pt2 == *str)
175 			break;
176 	}
177 	if (*pt2 == 0) {
178 #ifdef NET2_REGEX
179 		(void)free((char *)rep->rcmp);
180 #else
181 		regfree(&(rep->rcmp));
182 #endif
183 		(void)free((char *)rep);
184 		tty_warn(1, "Invalid replacement string %s", str);
185 		return -1;
186 	}
187 
188 	*pt2 = '\0';
189 
190 	/* Make sure to dup replacement, who knows where it came from! */
191 	if ((rep->nstr = strdup(pt1)) == NULL) {
192 #ifdef NET2_REGEX
193 		(void)free((char *)rep->rcmp);
194 #else
195 		regfree(&(rep->rcmp));
196 #endif
197 		(void)free((char *)rep);
198 		tty_warn(1, "Unable to allocate memory for replacement string");
199 		return -1;
200 	}
201 
202 	pt1 = pt2++;
203 	rep->flgs = 0;
204 
205 	/*
206 	 * set the options if any
207 	 */
208 	while (*pt2 != '\0') {
209 		switch(*pt2) {
210 		case 'g':
211 		case 'G':
212 			rep->flgs  |= GLOB;
213 			break;
214 		case 'p':
215 		case 'P':
216 			rep->flgs  |= PRNT;
217 			break;
218 		case 's':
219 		case 'S':
220 			rep->flgs  |= SYML;
221 			break;
222 		default:
223 #ifdef NET2_REGEX
224 			(void)free((char *)rep->rcmp);
225 #else
226 			regfree(&(rep->rcmp));
227 #endif
228 			(void)free((char *)rep);
229 			*pt1 = *str;
230 			tty_warn(1, "Invalid replacement string option %s",
231 			    str);
232 			return -1;
233 		}
234 		++pt2;
235 	}
236 
237 	/*
238 	 * all done, link it in at the end
239 	 */
240 	rep->fow = NULL;
241 	if (rephead == NULL) {
242 		reptail = rephead = rep;
243 		return 0;
244 	}
245 	reptail->fow = rep;
246 	reptail = rep;
247 	return 0;
248 }
249 
250 /*
251  * pat_add()
252  *	add a pattern match to the pattern match list. Pattern matches are used
253  *	to select which archive members are extracted. (They appear as
254  *	arguments to pax in the list and read modes). If no patterns are
255  *	supplied to pax, all members in the archive will be selected (and the
256  *	pattern match list is empty).
257  *
258  * Return:
259  *	0 if the pattern was added to the list, -1 otherwise
260  */
261 
262 int
263 pat_add(char *str, char *chdn)
264 {
265 	PATTERN *pt;
266 
267 	/*
268 	 * throw out the junk
269 	 */
270 	if ((str == NULL) || (*str == '\0')) {
271 		tty_warn(1, "Empty pattern string");
272 		return -1;
273 	}
274 
275 	/*
276 	 * allocate space for the pattern and store the pattern. the pattern is
277 	 * part of argv so do not bother to copy it, just point at it. Add the
278 	 * node to the end of the pattern list
279 	 */
280 	if ((pt = (PATTERN *)malloc(sizeof(PATTERN))) == NULL) {
281 		tty_warn(1, "Unable to allocate memory for pattern string");
282 		return -1;
283 	}
284 
285 	pt->pstr = str;
286 	pt->pend = NULL;
287 	pt->plen = strlen(str);
288 	pt->fow = NULL;
289 	pt->flgs = 0;
290 	pt->chdname = chdn;
291 	if (pathead == NULL) {
292 		pattail = pathead = pt;
293 		return 0;
294 	}
295 	pattail->fow = pt;
296 	pattail = pt;
297 	return 0;
298 }
299 
300 /*
301  * pat_chk()
302  *	complain if any the user supplied pattern did not result in a match to
303  *	a selected archive member.
304  */
305 
306 void
307 pat_chk(void)
308 {
309 	PATTERN *pt;
310 	int wban = 0;
311 
312 	/*
313 	 * walk down the list checking the flags to make sure MTCH was set,
314 	 * if not complain
315 	 */
316 	for (pt = pathead; pt != NULL; pt = pt->fow) {
317 		if (pt->flgs & MTCH)
318 			continue;
319 		if (!wban) {
320 			tty_warn(1, "WARNING! These patterns were not matched:");
321 			++wban;
322 		}
323 		(void)fprintf(stderr, "%s\n", pt->pstr);
324 	}
325 }
326 
327 /*
328  * pat_sel()
329  *	the archive member which matches a pattern was selected. Mark the
330  *	pattern as having selected an archive member. arcn->pat points at the
331  *	pattern that was matched. arcn->pat is set in pat_match()
332  *
333  *	NOTE: When the -c option is used, we are called when there was no match
334  *	by pat_match() (that means we did match before the inverted sense of
335  *	the logic). Now this seems really strange at first, but with -c we
336  *	need to keep track of those patterns that cause an archive member to
337  *	NOT be selected (it found an archive member with a specified pattern)
338  * Return:
339  *	0 if the pattern pointed at by arcn->pat was tagged as creating a
340  *	match, -1 otherwise.
341  */
342 
343 int
344 pat_sel(ARCHD *arcn)
345 {
346 	PATTERN *pt;
347 	PATTERN **ppt;
348 	int len;
349 
350 	/*
351 	 * if no patterns just return
352 	 */
353 	if ((pathead == NULL) || ((pt = arcn->pat) == NULL))
354 		return 0;
355 
356 	/*
357 	 * when we are NOT limited to a single match per pattern mark the
358 	 * pattern and return
359 	 */
360 	if (!nflag) {
361 		pt->flgs |= MTCH;
362 		return 0;
363 	}
364 
365 	/*
366 	 * we reach this point only when we allow a single selected match per
367 	 * pattern, if the pattern matches a directory and we do not have -d
368 	 * (dflag) we are done with this pattern. We may also be handed a file
369 	 * in the subtree of a directory. in that case when we are operating
370 	 * with -d, this pattern was already selected and we are done
371 	 */
372 	if (pt->flgs & DIR_MTCH)
373 		return 0;
374 
375 	if (!dflag && ((pt->pend != NULL) || (arcn->type == PAX_DIR))) {
376 		/*
377 		 * ok we matched a directory and we are allowing
378 		 * subtree matches but because of the -n only its children will
379 		 * match. This is tagged as a DIR_MTCH type.
380 		 * WATCH IT, the code assumes that pt->pend points
381 		 * into arcn->name and arcn->name has not been modified.
382 		 * If not we will have a big mess. Yup this is another kludge
383 		 */
384 
385 		/*
386 		 * if this was a prefix match, remove trailing part of path
387 		 * so we can copy it. Future matches will be exact prefix match
388 		 */
389 		if (pt->pend != NULL)
390 			*pt->pend = '\0';
391 
392 		if ((pt->pstr = strdup(arcn->name)) == NULL) {
393 			tty_warn(1, "Pattern select out of memory");
394 			if (pt->pend != NULL)
395 				*pt->pend = '/';
396 			pt->pend = NULL;
397 			return -1;
398 		}
399 
400 		/*
401 		 * put the trailing / back in the source string
402 		 */
403 		if (pt->pend != NULL) {
404 			*pt->pend = '/';
405 			pt->pend = NULL;
406 		}
407 		pt->plen = strlen(pt->pstr);
408 
409 		/*
410 		 * strip off any trailing /, this should really never happen
411 		 */
412 		len = pt->plen - 1;
413 		if (*(pt->pstr + len) == '/') {
414 			*(pt->pstr + len) = '\0';
415 			pt->plen = len;
416 		}
417 		pt->flgs = DIR_MTCH | MTCH;
418 		arcn->pat = pt;
419 		return 0;
420 	}
421 
422 	/*
423 	 * we are then done with this pattern, so we delete it from the list
424 	 * because it can never be used for another match.
425 	 * Seems kind of strange to do for a -c, but the pax spec is really
426 	 * vague on the interaction of -c, -n, and -d. We assume that when -c
427 	 * and the pattern rejects a member (i.e. it matched it) it is done.
428 	 * In effect we place the order of the flags as having -c last.
429 	 */
430 	pt = pathead;
431 	ppt = &pathead;
432 	while ((pt != NULL) && (pt != arcn->pat)) {
433 		ppt = &(pt->fow);
434 		pt = pt->fow;
435 	}
436 
437 	if (pt == NULL) {
438 		/*
439 		 * should never happen....
440 		 */
441 		tty_warn(1, "Pattern list inconsistent");
442 		return -1;
443 	}
444 	*ppt = pt->fow;
445 	(void)free((char *)pt);
446 	arcn->pat = NULL;
447 	return 0;
448 }
449 
450 /*
451  * pat_match()
452  *	see if this archive member matches any supplied pattern, if a match
453  *	is found, arcn->pat is set to point at the potential pattern. Later if
454  *	this archive member is "selected" we process and mark the pattern as
455  *	one which matched a selected archive member (see pat_sel())
456  * Return:
457  *	0 if this archive member should be processed, 1 if it should be
458  *	skipped and -1 if we are done with all patterns (and pax should quit
459  *	looking for more members)
460  */
461 
462 int
463 pat_match(ARCHD *arcn)
464 {
465 	PATTERN *pt;
466 
467 	arcn->pat = NULL;
468 
469 	/*
470 	 * if there are no more patterns and we have -n (and not -c) we are
471 	 * done. otherwise with no patterns to match, matches all
472 	 */
473 	if (pathead == NULL) {
474 		if (nflag && !cflag)
475 			return -1;
476 		return 0;
477 	}
478 
479 	/*
480 	 * have to search down the list one at a time looking for a match.
481 	 */
482 	pt = pathead;
483 	while (pt != NULL) {
484 		/*
485 		 * check for a file name match unless we have DIR_MTCH set in
486 		 * this pattern then we want a prefix match
487 		 */
488 		if (pt->flgs & DIR_MTCH) {
489 			/*
490 			 * this pattern was matched before to a directory
491 			 * as we must have -n set for this (but not -d). We can
492 			 * only match CHILDREN of that directory so we must use
493 			 * an exact prefix match (no wildcards).
494 			 */
495 			if ((arcn->name[pt->plen] == '/') &&
496 			    (strncmp(pt->pstr, arcn->name, pt->plen) == 0))
497 				break;
498 		} else if (fn_match(pt->pstr, arcn->name, &pt->pend) == 0)
499 			break;
500 		pt = pt->fow;
501 	}
502 
503 	/*
504 	 * return the result, remember that cflag (-c) inverts the sense of a
505 	 * match
506 	 */
507 	if (pt == NULL)
508 		return cflag ? 0 : 1;
509 
510 	/*
511 	 * we had a match, now when we invert the sense (-c) we reject this
512 	 * member. However we have to tag the pattern a being successful, (in a
513 	 * match, not in selecting an archive member) so we call pat_sel()
514 	 * here.
515 	 */
516 	arcn->pat = pt;
517 	if (!cflag)
518 		return 0;
519 
520 	if (pat_sel(arcn) < 0)
521 		return -1;
522 	arcn->pat = NULL;
523 	return 1;
524 }
525 
526 /*
527  * fn_match()
528  * Return:
529  *	0 if this archive member should be processed, 1 if it should be
530  *	skipped and -1 if we are done with all patterns (and pax should quit
531  *	looking for more members)
532  *	Note: *pend may be changed to show where the prefix ends.
533  */
534 
535 static int
536 fn_match(char *pattern, char *string, char **pend)
537 {
538 	char c;
539 	char test;
540 
541 	*pend = NULL;
542 	for (;;) {
543 		switch (c = *pattern++) {
544 		case '\0':
545 			/*
546 			 * Ok we found an exact match
547 			 */
548 			if (*string == '\0')
549 				return 0;
550 
551 			/*
552 			 * Check if it is a prefix match
553 			 */
554 			if ((dflag == 1) || (*string != '/'))
555 				return -1;
556 
557 			/*
558 			 * It is a prefix match, remember where the trailing
559 			 * / is located
560 			 */
561 			*pend = string;
562 			return 0;
563 		case '?':
564 			if ((test = *string++) == '\0')
565 				return (-1);
566 			break;
567 		case '*':
568 			c = *pattern;
569 			/*
570 			 * Collapse multiple *'s.
571 			 */
572 			while (c == '*')
573 				c = *++pattern;
574 
575 			/*
576 			 * Optimized hack for pattern with a * at the end
577 			 */
578 			if (c == '\0')
579 				return (0);
580 
581 			/*
582 			 * General case, use recursion.
583 			 */
584 			while ((test = *string) != '\0') {
585 				if (!fn_match(pattern, string, pend))
586 					return (0);
587 				++string;
588 			}
589 			return (-1);
590 		case '[':
591 			/*
592 			 * range match
593 			 */
594 			if (((test = *string++) == '\0') ||
595 			    ((pattern = range_match(pattern, test)) == NULL))
596 				return (-1);
597 			break;
598 		case '\\':
599 		default:
600 			if (c != *string++)
601 				return (-1);
602 			break;
603 		}
604 	}
605 	/* NOTREACHED */
606 }
607 
608 static char *
609 range_match(char *pattern, int test)
610 {
611 	char c;
612 	char c2;
613 	int negate;
614 	int ok = 0;
615 
616 	if ((negate = (*pattern == '!')) != 0)
617 		++pattern;
618 
619 	while ((c = *pattern++) != ']') {
620 		/*
621 		 * Illegal pattern
622 		 */
623 		if (c == '\0')
624 			return (NULL);
625 
626 		if ((*pattern == '-') && ((c2 = pattern[1]) != '\0') &&
627 		    (c2 != ']')) {
628 			if ((c <= test) && (test <= c2))
629 				ok = 1;
630 			pattern += 2;
631 		} else if (c == test)
632 			ok = 1;
633 	}
634 	return (ok == negate ? NULL : pattern);
635 }
636 
637 /*
638  * mod_name()
639  *	modify a selected file name. first attempt to apply replacement string
640  *	expressions, then apply interactive file rename. We apply replacement
641  *	string expressions to both filenames and file links (if we didn't the
642  *	links would point to the wrong place, and we could never be able to
643  *	move an archive that has a file link in it). When we rename files
644  *	interactively, we store that mapping (old name to user input name) so
645  *	if we spot any file links to the old file name in the future, we will
646  *	know exactly how to fix the file link.
647  * Return:
648  *	0 continue to  process file, 1 skip this file, -1 pax is finished
649  */
650 
651 int
652 mod_name(ARCHD *arcn, int flags)
653 {
654 	int res = 0;
655 
656 	if (secure) {
657 		if (checkdotdot(arcn->name)) {
658 			tty_warn(0, "Ignoring file containing `..' (%s)",
659 				arcn->name);
660 			return 1;
661 		}
662 #ifdef notdef
663 		if (checkdotdot(arcn->ln_name)) {
664 			tty_warn(0, "Ignoring link containing `..' (%s)",
665 				arcn->ln_name);
666 			return 1;
667 		}
668 #endif
669 	}
670 
671 	/*
672 	 * IMPORTANT: We have a problem. what do we do with symlinks?
673 	 * Modifying a hard link name makes sense, as we know the file it
674 	 * points at should have been seen already in the archive (and if it
675 	 * wasn't seen because of a read error or a bad archive, we lose
676 	 * anyway). But there are no such requirements for symlinks. On one
677 	 * hand the symlink that refers to a file in the archive will have to
678 	 * be modified to so it will still work at its new location in the
679 	 * file system. On the other hand a symlink that points elsewhere (and
680 	 * should continue to do so) should not be modified. There is clearly
681 	 * no perfect solution here. So we handle them like hardlinks. Clearly
682 	 * a replacement made by the interactive rename mapping is very likely
683 	 * to be correct since it applies to a single file and is an exact
684 	 * match. The regular expression replacements are a little harder to
685 	 * justify though. We claim that the symlink name is only likely
686 	 * to be replaced when it points within the file tree being moved and
687 	 * in that case it should be modified. what we really need to do is to
688 	 * call an oracle here. :)
689 	 */
690 	if (rephead != NULL) {
691 		flags |= (flags & RENM) ? PRNT : 0;
692 		/*
693 		 * we have replacement strings, modify the name and the link
694 		 * name if any.
695 		 */
696 		if ((res = rep_name(arcn->name, sizeof(arcn->name),
697 			&(arcn->nlen), flags)) != 0)
698 			return res;
699 
700 		if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
701 		    (arcn->type == PAX_HRG)) &&
702 		    ((res = rep_name(arcn->ln_name,
703 		    sizeof(arcn->ln_name), &(arcn->ln_nlen),
704 		    flags | (arcn->type == PAX_SLK ? SYML : 0))) != 0))
705 			return res;
706 	}
707 
708 	if (iflag) {
709 		/*
710 		 * perform interactive file rename, then map the link if any
711 		 */
712 		if ((res = tty_rename(arcn)) != 0)
713 			return res;
714 		if ((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
715 		    (arcn->type == PAX_HRG))
716 			sub_name(arcn->ln_name, &(arcn->ln_nlen), sizeof(arcn->ln_name));
717 	}
718 
719 	/*
720 	 * Strip off leading '/' if appropriate.
721 	 * Currently, this option is only set for the tar format.
722 	 */
723 	if (rmleadslash && arcn->name[0] == '/') {
724 		if (arcn->name[1] == '\0') {
725 			arcn->name[0] = '.';
726 		} else {
727 			(void)memmove(arcn->name, &arcn->name[1],
728 			    strlen(arcn->name));
729 			arcn->nlen--;
730 		}
731 		if (rmleadslash < 2) {
732 			rmleadslash = 2;
733 			tty_warn(0, "Removing leading / from absolute path names in the archive");
734 		}
735 	}
736 	if (rmleadslash && arcn->ln_name[0] == '/' &&
737 	    (arcn->type == PAX_HLK || arcn->type == PAX_HRG)) {
738 		if (arcn->ln_name[1] == '\0') {
739 			arcn->ln_name[0] = '.';
740 		} else {
741 			(void)memmove(arcn->ln_name, &arcn->ln_name[1],
742 			    strlen(arcn->ln_name));
743 			arcn->ln_nlen--;
744 		}
745 		if (rmleadslash < 2) {
746 			rmleadslash = 2;
747 			tty_warn(0, "Removing leading / from absolute path names in the archive");
748 		}
749 	}
750 
751 	return res;
752 }
753 
754 /*
755  * tty_rename()
756  *	Prompt the user for a replacement file name. A "." keeps the old name,
757  *	a empty line skips the file, and an EOF on reading the tty, will cause
758  *	pax to stop processing and exit. Otherwise the file name input, replaces
759  *	the old one.
760  * Return:
761  *	0 process this file, 1 skip this file, -1 we need to exit pax
762  */
763 
764 static int
765 tty_rename(ARCHD *arcn)
766 {
767 	char tmpname[PAXPATHLEN+2];
768 	int res;
769 
770 	/*
771 	 * prompt user for the replacement name for a file, keep trying until
772 	 * we get some reasonable input. Archives may have more than one file
773 	 * on them with the same name (from updates etc). We print verbose info
774 	 * on the file so the user knows what is up.
775 	 */
776 	tty_prnt("\nATTENTION: %s interactive file rename operation.\n", argv0);
777 
778 	for (;;) {
779 		ls_tty(arcn);
780 		tty_prnt("Input new name, or a \".\" to keep the old name, ");
781 		tty_prnt("or a \"return\" to skip this file.\n");
782 		tty_prnt("Input > ");
783 		if (tty_read(tmpname, sizeof(tmpname)) < 0)
784 			return -1;
785 		if (strcmp(tmpname, "..") == 0) {
786 			tty_prnt("Try again, illegal file name: ..\n");
787 			continue;
788 		}
789 		if (strlen(tmpname) > PAXPATHLEN) {
790 			tty_prnt("Try again, file name too long\n");
791 			continue;
792 		}
793 		break;
794 	}
795 
796 	/*
797 	 * empty file name, skips this file. a "." leaves it alone
798 	 */
799 	if (tmpname[0] == '\0') {
800 		tty_prnt("Skipping file.\n");
801 		return 1;
802 	}
803 	if ((tmpname[0] == '.') && (tmpname[1] == '\0')) {
804 		tty_prnt("Processing continues, name unchanged.\n");
805 		return 0;
806 	}
807 
808 	/*
809 	 * ok the name changed. We may run into links that point at this
810 	 * file later. we have to remember where the user sent the file
811 	 * in order to repair any links.
812 	 */
813 	tty_prnt("Processing continues, name changed to: %s\n", tmpname);
814 	res = add_name(arcn->name, arcn->nlen, tmpname);
815 	arcn->nlen = strlcpy(arcn->name, tmpname, sizeof(arcn->name));
816 	if (res < 0)
817 		return -1;
818 	return 0;
819 }
820 
821 /*
822  * set_dest()
823  *	fix up the file name and the link name (if any) so this file will land
824  *	in the destination directory (used during copy() -rw).
825  * Return:
826  *	0 if ok, -1 if failure (name too long)
827  */
828 
829 int
830 set_dest(ARCHD *arcn, char *dest_dir, int dir_len)
831 {
832 	if (fix_path(arcn->name, &(arcn->nlen), dest_dir, dir_len) < 0)
833 		return -1;
834 
835 	/*
836 	 * It is really hard to deal with symlinks here, we cannot be sure
837 	 * if the name they point was moved (or will be moved). It is best to
838 	 * leave them alone.
839 	 */
840 	if ((arcn->type != PAX_HLK) && (arcn->type != PAX_HRG))
841 		return 0;
842 
843 	if (fix_path(arcn->ln_name, &(arcn->ln_nlen), dest_dir, dir_len) < 0)
844 		return -1;
845 	return 0;
846 }
847 
848 /*
849  * fix_path
850  *	concatenate dir_name and or_name and store the result in or_name (if
851  *	it fits). This is one ugly function.
852  * Return:
853  *	0 if ok, -1 if the final name is too long
854  */
855 
856 static int
857 fix_path( char *or_name, int *or_len, char *dir_name, int dir_len)
858 {
859 	char *src;
860 	char *dest;
861 	char *start;
862 	int len;
863 
864 	/*
865 	 * we shift the or_name to the right enough to tack in the dir_name
866 	 * at the front. We make sure we have enough space for it all before
867 	 * we start. since dest always ends in a slash, we skip of or_name
868 	 * if it also starts with one.
869 	 */
870 	start = or_name;
871 	src = start + *or_len;
872 	dest = src + dir_len;
873 	if (*start == '/') {
874 		++start;
875 		--dest;
876 	}
877 	if ((len = dest - or_name) > PAXPATHLEN) {
878 		tty_warn(1, "File name %s/%s, too long", dir_name, start);
879 		return -1;
880 	}
881 	*or_len = len;
882 
883 	/*
884 	 * enough space, shift
885 	 */
886 	while (src >= start)
887 		*dest-- = *src--;
888 	src = dir_name + dir_len - 1;
889 
890 	/*
891 	 * splice in the destination directory name
892 	 */
893 	while (src >= dir_name)
894 		*dest-- = *src--;
895 
896 	*(or_name + len) = '\0';
897 	return 0;
898 }
899 
900 /*
901  * rep_name()
902  *	walk down the list of replacement strings applying each one in order.
903  *	when we find one with a successful substitution, we modify the name
904  *	as specified. if required, we print the results. if the resulting name
905  *	is empty, we will skip this archive member. We use the regexp(3)
906  *	routines (regexp() ought to win a prize as having the most cryptic
907  *	library function manual page).
908  *	--Parameters--
909  *	name is the file name we are going to apply the regular expressions to
910  *	(and may be modified)
911  *	namelen the size of the name buffer.
912  *	nlen is the length of this name (and is modified to hold the length of
913  *	the final string).
914  *	prnt is a flag that says whether to print the final result.
915  * Return:
916  *	0 if substitution was successful, 1 if we are to skip the file (the name
917  *	ended up empty)
918  */
919 
920 static int
921 rep_name(char *name, size_t namelen, int *nlen, int flags)
922 {
923 	REPLACE *pt;
924 	char *inpt;
925 	char *outpt;
926 	char *endpt;
927 	char *rpt;
928 	int found = 0;
929 	int res;
930 #ifndef NET2_REGEX
931 	regmatch_t pm[MAXSUBEXP];
932 #endif
933 	char nname[PAXPATHLEN+1];	/* final result of all replacements */
934 	char buf1[PAXPATHLEN+1];	/* where we work on the name */
935 
936 	/*
937 	 * copy the name into buf1, where we will work on it. We need to keep
938 	 * the orig string around so we can print out the result of the final
939 	 * replacement. We build up the final result in nname. inpt points at
940 	 * the string we apply the regular expression to. prnt is used to
941 	 * suppress printing when we handle replacements on the link field
942 	 * (the user already saw that substitution go by)
943 	 */
944 	pt = rephead;
945 	(void)strcpy(buf1, name);
946 	inpt = buf1;
947 	outpt = nname;
948 	endpt = outpt + PAXPATHLEN;
949 
950 	/*
951 	 * try each replacement string in order
952 	 */
953 	while (pt != NULL) {
954 		do {
955 			if ((flags & SYML) && (pt->flgs & SYML))
956 				continue;
957 			/*
958 			 * check for a successful substitution, if not go to
959 			 * the next pattern, or cleanup if we were global
960 			 */
961 #ifdef NET2_REGEX
962 			if (regexec(pt->rcmp, inpt) == 0)
963 #else
964 			if (regexec(&(pt->rcmp), inpt, MAXSUBEXP, pm, 0) != 0)
965 #endif
966 				break;
967 
968 			/*
969 			 * ok we found one. We have three parts, the prefix
970 			 * which did not match, the section that did and the
971 			 * tail (that also did not match). Copy the prefix to
972 			 * the final output buffer (watching to make sure we
973 			 * do not create a string too long).
974 			 */
975 			found = 1;
976 #ifdef NET2_REGEX
977 			rpt = pt->rcmp->startp[0];
978 #else
979 			rpt = inpt + pm[0].rm_so;
980 #endif
981 
982 			while ((inpt < rpt) && (outpt < endpt))
983 				*outpt++ = *inpt++;
984 			if (outpt == endpt)
985 				break;
986 
987 			/*
988 			 * for the second part (which matched the regular
989 			 * expression) apply the substitution using the
990 			 * replacement string and place it the prefix in the
991 			 * final output. If we have problems, skip it.
992 			 */
993 			if ((res =
994 #ifdef NET2_REGEX
995 			    resub(pt->rcmp,pt->nstr,outpt,endpt)
996 #else
997 			    resub(&(pt->rcmp),pm,pt->nstr,inpt, outpt,endpt)
998 #endif
999 			    ) < 0) {
1000 				if (flags & PRNT)
1001 					tty_warn(1, "Replacement name error %s",
1002 					    name);
1003 				return 1;
1004 			}
1005 			outpt += res;
1006 
1007 			/*
1008 			 * we set up to look again starting at the first
1009 			 * character in the tail (of the input string right
1010 			 * after the last character matched by the regular
1011 			 * expression (inpt always points at the first char in
1012 			 * the string to process). If we are not doing a global
1013 			 * substitution, we will use inpt to copy the tail to
1014 			 * the final result. Make sure we do not overrun the
1015 			 * output buffer
1016 			 */
1017 #ifdef NET2_REGEX
1018 			inpt = pt->rcmp->endp[0];
1019 #else
1020 			inpt += pm[0].rm_eo - pm[0].rm_so;
1021 #endif
1022 
1023 			if ((outpt == endpt) || (*inpt == '\0'))
1024 				break;
1025 
1026 			/*
1027 			 * if the user wants global we keep trying to
1028 			 * substitute until it fails, then we are done.
1029 			 */
1030 		} while (pt->flgs & GLOB);
1031 
1032 		if (found)
1033 			break;
1034 
1035 		/*
1036 		 * a successful substitution did NOT occur, try the next one
1037 		 */
1038 		pt = pt->fow;
1039 	}
1040 
1041 	if (found) {
1042 		/*
1043 		 * we had a substitution, copy the last tail piece (if there is
1044 		 * room) to the final result
1045 		 */
1046 		while ((outpt < endpt) && (*inpt != '\0'))
1047 			*outpt++ = *inpt++;
1048 
1049 		*outpt = '\0';
1050 		if ((outpt == endpt) && (*inpt != '\0')) {
1051 			if (flags & PRNT)
1052 				tty_warn(1,"Replacement name too long %s >> %s",
1053 				    name, nname);
1054 			return 1;
1055 		}
1056 
1057 		/*
1058 		 * inform the user of the result if wanted
1059 		 */
1060 		if ((flags & PRNT) && (pt->flgs & PRNT)) {
1061 			if (*nname == '\0')
1062 				(void)fprintf(stderr,"%s >> <empty string>\n",
1063 				    name);
1064 			else
1065 				(void)fprintf(stderr,"%s >> %s\n", name, nname);
1066 		}
1067 
1068 		/*
1069 		 * if empty inform the caller this file is to be skipped
1070 		 * otherwise copy the new name over the orig name and return
1071 		 */
1072 		if (*nname == '\0')
1073 			return 1;
1074 		if (flags & RENM)
1075 			*nlen = strlcpy(name, nname, namelen);
1076 	}
1077 	return 0;
1078 }
1079 
1080 
1081 /*
1082  * checkdotdot()
1083  *	Return true if a component of the name contains a reference to ".."
1084  */
1085 static int
1086 checkdotdot(const char *name)
1087 {
1088 	const char *p;
1089 	/* 1. "..{[/],}" */
1090 	if (name[0] == '.' && name[1] == '.' &&
1091 	    (name[2] == '/' || name[2] == '\0'))
1092 		return 1;
1093 
1094 	/* 2. "*[/]..[/]*" */
1095 	if (strstr(name, "/../") != NULL)
1096 		return 1;
1097 
1098 	/* 3. "*[/].." */
1099 	for (p = name; *p; p++)
1100 		continue;
1101 	if (p - name < 3)
1102 		return 0;
1103 	if (p[-1] == '.' && p[-2] == '.' && p[-3] == '/')
1104 		return 1;
1105 
1106 	return 0;
1107 }
1108 
1109 #ifdef NET2_REGEX
1110 /*
1111  * resub()
1112  *	apply the replacement to the matched expression. expand out the old
1113  *	style ed(1) subexpression expansion.
1114  * Return:
1115  *	-1 if error, or the number of characters added to the destination.
1116  */
1117 
1118 static int
1119 resub(regexp *prog, char *src, char *dest, char *destend)
1120 {
1121 	char *spt;
1122 	char *dpt;
1123 	char c;
1124 	int no;
1125 	int len;
1126 
1127 	spt = src;
1128 	dpt = dest;
1129 	while ((dpt < destend) && ((c = *spt++) != '\0')) {
1130 		if (c == '&')
1131 			no = 0;
1132 		else if ((c == '\\') && (*spt >= '0') && (*spt <= '9'))
1133 			no = *spt++ - '0';
1134 		else {
1135 			if ((c == '\\') && ((*spt == '\\') || (*spt == '&')))
1136 				c = *spt++;
1137 			*dpt++ = c;
1138 			continue;
1139 		}
1140 		if ((prog->startp[no] == NULL) || (prog->endp[no] == NULL) ||
1141 		    ((len = prog->endp[no] - prog->startp[no]) <= 0))
1142 			continue;
1143 
1144 		/*
1145 		 * copy the subexpression to the destination.
1146 		 * fail if we run out of space or the match string is damaged
1147 		 */
1148 		if (len > (destend - dpt))
1149 			return (-1);
1150 		strncpy(dpt, prog->startp[no], len);
1151 		dpt += len;
1152 	}
1153 	return dpt - dest;
1154 }
1155 
1156 #else
1157 
1158 /*
1159  * resub()
1160  *	apply the replacement to the matched expression. expand out the old
1161  *	style ed(1) subexpression expansion.
1162  * Return:
1163  *	-1 if error, or the number of characters added to the destination.
1164  */
1165 
1166 static int
1167 resub(regex_t *rp, regmatch_t *pm, char *src, char *txt, char *dest,
1168 	char *destend)
1169 {
1170 	char *spt;
1171 	char *dpt;
1172 	char c;
1173 	regmatch_t *pmpt;
1174 	int len;
1175 	int subexcnt;
1176 
1177 	spt =  src;
1178 	dpt = dest;
1179 	subexcnt = rp->re_nsub;
1180 	while ((dpt < destend) && ((c = *spt++) != '\0')) {
1181 		/*
1182 		 * see if we just have an ordinary replacement character
1183 		 * or we refer to a subexpression.
1184 		 */
1185 		if (c == '&') {
1186 			pmpt = pm;
1187 		} else if ((c == '\\') && (*spt >= '1') && (*spt <= '9')) {
1188 			/*
1189 			 * make sure there is a subexpression as specified
1190 			 */
1191 			if ((len = *spt++ - '0') > subexcnt)
1192 				return -1;
1193 			pmpt = pm + len;
1194 		} else {
1195 			/*
1196 			 * Ordinary character, just copy it
1197 			 */
1198 			if ((c == '\\') && ((*spt == '\\') || (*spt == '&')))
1199 				c = *spt++;
1200 			*dpt++ = c;
1201 			continue;
1202 		}
1203 
1204 		/*
1205 		 * continue if the subexpression is bogus
1206 		 */
1207 		if ((pmpt->rm_so < 0) || (pmpt->rm_eo < 0) ||
1208 		    ((len = pmpt->rm_eo - pmpt->rm_so) <= 0))
1209 			continue;
1210 
1211 		/*
1212 		 * copy the subexpression to the destination.
1213 		 * fail if we run out of space or the match string is damaged
1214 		 */
1215 		if (len > (destend - dpt))
1216 			return -1;
1217 		strncpy(dpt, txt + pmpt->rm_so, len);
1218 		dpt += len;
1219 	}
1220 	return dpt - dest;
1221 }
1222 #endif
1223